摘要
环境生物学家目前面临的任务之一是就酸雨对水体和水生生物的冲击作出预测。本文主要介绍酸雨分布最广、危害严重的地区,并对水生生物的影响作出分析。研究表明一个湖泊及其流域中和酸雨所进入的酸的容量,主要取决于汇水区基岩的组成。湖、河酸化所带来的最明显的生物学冲击是鱼类种群的消失或减少。而食物网中各个营养级的生物也可能受到影响。生物的数量和种类会减少,结果随着整个水生态系统的破坏,水体的初级生产力和分解作用受到伤害。 我们所进行的研究表明:鲢、餹、鲤对酸的相对敏感性是受精卵>鱼苗>鱼种;鲢鱼的96小时LC_(50)分别是pH5.34,4.51及3.80。酸雨对大型溞的急性毒性,24小时LC_(50)是pH4.06±0.19;48小时LC_(50)是pH4.94±0.20。椭园萝卜螺对酸的96小时累积死亡率分别是:pH3.6时100％,pH3.8时60％,pH4.0时20％以及pH4.2时10％。 作者对今后需要进行的研究课题提出了建议。
Acid rain,caused by the emission of sulfur and nitrogen oxides to the atmosphere and their subsequent transformation to sulfates and nitrates,is one of the most widely known environmental issues of the day. The potential consequences of increasingly widespread acid rain demand that this problem should be carefully studied. One of the most pressing issues currently facing environmental biologist is the need to predict the impact of acid rain on water bodies and the effect of acid deposition on aquatic organisms. This paper focuses on the area where acid deposition is most widespread and deleterious and analyzes the effects on aquatic organisms.Depending on various factors, lakes and watersheds exihibit a range of sensitivity to acidification.Studies indicate that the capability of a lake and its drainage basin to neutralize the acid inputs of acid rain is largely predicated on the composition of the bedrock of the, watershed.The death of fish in acidified freshwater lakes and streams has been more thoroughly studied, both in laboratory and in the field, than any other aspect of lake and stream acidification.Elimination or reduction of a fish population is the most obvious biological impact associated with acidification of freshwater lakes and streams. Organisms at all trophic levels within the iocd web may be affected. Species can be reduced in number and variety, and primary production and decomposition may be impaired with a resultant disruption of the entire aquatic ecosystem.Our experiments indicate that the order of relative sensitivity of silver carp (Hypophthalmichthys molitrix),bighead (Aristichthys nobi/is) and grass carp(Cte-nopharyngodon idella) to acid is fertilized egg>fry>fingerling. The values of 96 hr LC50 of silver carp are pH5.34,4.51 and 3.80 respectively. The acute effects of acid rain on Daphnia magna are pH4.66±0.19 (24 hr LC50) and pH4.90±0.20 (48 hr LC50). The 96 hr accumulated death rates of Radix swinhoei to acid are 100%, 60%, 20% and 10% at pH3.6,3.8,4.0 and 4.2 respectively.Several topics for future research have been suggested by the author.
出处
《生态学报》
CAS
CSCD
北大核心
1989年第1期77-83,共7页
Acta Ecologica Sinica
关键词
酸雨
水生生物
生态系统
acid rain, watersheds, aquatic ecosystem, acidification, effect.
